Method and apparatus for generating and controlling heat



` May 109 W. s. HADAWAY, JR METHOD AND APPARATUS FOR GENERATING AND CONTROLLING HEAT Filed Dec. 16, 1921 ATTORNEY.

Patented May l0, i927.

narra r if itil g WILLIAM S. HADAWAY, JR., OF NEW ROCHELLE, NEW YORK.

METHOD AND APPARATUS FOR GENERATNG AND CONTROLLIN'G HEAT.

Application :tiled December 16, 1921.

This invention relates` to the generation and control of heat.

`lroadly stated it is an object of the present invention to provide an improved form of heat generator, and a new method of initiating, maintaining and controlling combustion.

A feature of the invention relates to the en'iployment of relatively inexpensive and easily obtained mediums as active agents, resulting in great economy .in the generation of heat.

Another feature relates to improved methods of treating an active fluid agent, whereby it may be caused automatically to initiated combustion and is itself employed to maintain the combustion in an improved and efficient manner.

Another feature relates to the provision of means responsive to the generated heat foil controlling the temperature of thev incoming fluid agent, whereby combustion may be eliieiently maintained independent of the starting` means.

Another object relates to the provision of temperature responsive means automatically controlling the active fluid agent. The control may relate to varying one or more of the characteristics of the agent. In some cases the temperature responsive means may control the temperature at which the agent shall be introduced, in other cases the quantity may be controlled thereby. and in still other cases both temperature and quantity may be controlled.

Still another object relates to the employment of an incoming active agent to provide a. forced draft in order to insure their passage through a fulgurite tube and in order to circulate the products of combustion through exterior' utilities. Ash compartments may be provided into which the ash is blown by the stream of incoming medium`I whereby the combustion chamber may be automatically cleaned out. This pressure of the incomingleases forces ashes, away from the fule'urite and keeps the fuel clean in the Zone where the gases enter.

Other objects will appear from the fol lowing description of the invention taken in connection with the drawings.

leferringi to the drawings:

Fin. l shows diagrammatically a. heat grenorator, preheater and control means there for;

Fig. 2 shows details of the preheater;

Serial No. 522,948.

Fig. 3 shows an electrically insulated va por joint;

Fig. lshows a modilied form of system; and

Fig. 5 shows a section on the line 5--5 yof Fig. 4l.

Lilre'characters of reference denote corresponding` parts in all the figures of the drawing. l

Referringy to the drawing, there is shown a furnace 10, a heat exchange member 35, a controller 12. and suitable connecting pas-4 sages as will be subsequently set forth. The

active medium may be supplied from any suitable source (not shown) which may be of any desired form. such as an air pump or steam boiler or the like adapted to emit a continuous supply of a fluid (gaseous) medium into an outlet passage 20. The u'iedium selected for use should preferably he relatively inexpensive and such as can be readily obtained in suitably large quantities. It should also be of such chemical nature that it may be separated or dissociated into its constituent elements readily and conveniently. and when so separated or dissociated one or more of the elements should be capable of maintaining combus tion. Air or steam (water vapor) fulfill these requirements and may therefore be employed although it is understood that the practice of the invention is not limited to the use of air or steam` but that any equivalent medium may be employed.

The passage 2O leads to a heat exchange Amember which comprises a pair of concent-ric tubes. The inner tube 36 to one end of which .the passage 2O is connected, extends through the heat exchange member` 35 and its discharge end connects with a passage or tube 37. The arrangement is such that the vapor is` conducted through the inner tube 36. through the length of the tube into the passan'e 3'?. The space 38 between the inner tube and the outer tube forminn' the heat exchange member 35 is preferably filled with a ,granular mass of refractory material such as earborundum or the like, which may be maintained in position therein in any desired manner, as for example, by means of a pair of screens 39.

The passage 37 leads to the furnace 10 which comprises a casing 40 of refractory material which casing is open at the top. The outer surface of the casing 40 may be covered Awith a suitable metal covering.

Within this easing is an inner casing 41 of similar refractory material also open at the top. A cover 44 of refractory material is constructed to seal the top of the casing-s and has a dependent boss 45 which projects into the inner casing.;` slightly in order to position the cover, and to seal the furnace more effectively..

Positioned within the lower portion of the interior of the inner receptacle 41 is a preheater 11 which may comprise one or more tubes or passages 14, 14 coiled land arranged in a heat insulating body 15 (Fig. 2) in any 'desired forni. As shown, a plurality of tubes or passages is provlded, each forming a helix, and, these helices may be bent into seniicircular form (see Fig. 2). The heater tubes 14 are preferably formed of a nickel chromium alloy or other suitable resistance material which is capable of withstanding high temperature. A junction 21 joins the two coils of the outer pair and forms vapor conducting .passages from the assage 37 into the coils. Sii'nilar junction oxes such as 22, 23, connect the oppositely disposed ends of the outer pair with corresponding ends of the next inner pair. The arrangement is such that the vapor is conducted through the passages of the preheater and emerges therefrom into a connecting passage 25.

Referring to Fig. 3 each junction box such as 21, is provided with a hollow insulatingl block 30 with the interior chamber of which the respective vapor passages are operatively connected. A pair of metal flanges 31, 32 are secured to the tubes or passages 14, and are each suitably -fastened independently to the block 30. Conductors such as 33, 34 electrically interconnect the conducting passages in :i sequence preferably different from that in which the vapor flows therethrough. A hollow heater or rglower 53 is positioned above the middle portion of the prelieater 11. This is a perforated tube preferably in the form" of a fulgurite and made of oxides of magnesia or other material which may be operated at a glowing teinperature. The electric conductivity of the fulgurite increases with increase in its temperature. Thetube may be bent into a U-shape, the passage 25 being connected with one end thereof. A plurality of lateral passages extend radially from the interior of the tube to its surface for the emission of the heated Huid medium. In the space around the tube there is inserted a supply of fuel 46 such as briquettes or pieces of coke or the like.

Surrounding the casing 40 and in spaced relation therewith, there may be provided a suitable casing S() forming an annulaichamber between it and the casing- 40. A

`horizontal partitionSl divides the chamber into an upper ash compartment 82 and a lower ash eon'ipartment 83. Suitable hingedY trap doors such as 84 provide means for cleaning out the compartments 82, 83 whenever desired.

The upper compartment 82 is connected with the interior of the inner casing 41 at a point above the level of the fuel 46, by means of a passage such as Similarly the lower compartment 83 is connected with the interior of the inner casing 41 at a point opposite the bottom portion ol the -l'uel 46 by a passage such as Sti. The con'il'iartments are provided with screens such as 8T, 88 through which the vapors pass.

The passage 37 has an interposed control valve 90 whereby the rate of flow or pressure of the fluid medium passinir through the passage may be regulated. l`he valve may be of any conventional construction, and is preferably adjusted so as to permit at least some flow at all positions of its stem. The stem maybe rotated or otherwise operated by a suitable solenoid or electromagnet 91 connected in shunt with the resister of the preheater 11. The arrangement is such that when the magnet 91 is deenergized the retractile spring maintains the valve in its fully open position, so that the medium flows at a predetermined rate, and when the magnet is actuated and its armature attracted the valve passage is restricted, thus reducing the flow of medium.

Extending outwardly from the compartment 82 is a discharge passage 54 which leads to one port of a three way valve 55.`

Another discharge outlet 56 is provided which emerges from the compartment 83. This outlet connects with a second port of the valve 55. The third port of the valve iS connected by means of passages 57, 5S to a heat actuated utility 59. It is understood that any desired type of utility may be employed, that shown being a flat plate of conventional form.

The electrical connections of the heater 53 are shown in Fig. 1. A source of energy 60 may alsobe connected to the dissociation heater 53 through a switch 63 but in series with this circuit there is provided electroresponsive means whereby a contact may be variably controlled according to the intensity of the current flowing. In the construction shown a marginal relay 64k is eniployed adapted to operate only when the current through its winding,Y exceeds a predetermined value. It is undersmod, however, that any desired. form of electroresponsive means maivv be employed.- The contact 65 controls a circuit from the source of energy 60 to the terminals of the passages 14 of the preheater 11. As shown the various passages forming;r the preheater ll are electrically in series Vwith each other. but it is understood that any desired method of arrangement of these passages may be employed.

In the modified form of system shown in Figs. 4 and 5, the heatl exchange member is furnace.

provided with one or more conductors 70, which are insulated from each other and from other portions of the device in any well known manner. The terminals of the conductors are brought out to insulated binding posts and they are connected into a circuit including the contact 65, the source of electric energy and the control switch 63, in the same manner as the resistor tubes 14. An inlet connection 71 for the inner tube 36 is connected to a needle valve 72 and through it to .a supply pipe 73 to a source of supply of active medium. If steam is the active agent en'iployed, the pipe 73 may be connected to a suitable reservoir of water. A sulficient pressure of say two or three pounds,` is preferably impressed upon the medium to insure flow of the liquid- The inner tube 36 is connected between the source of vapor and the inlet of the furnace 10 and the outer spacev is connected between the outlets of the furnace and the utility 59.

In the operation of the system of Figs. 1, 2 and 3, the fluid agent, as for example, air under pressure, is supplied through the passage 20. Assuming that air is the agent employed, it passes through the inner tube 36 of the heat exchange member 35, the passage 37, the preheater 11 and enters the lower portion of the furnace 10 through the dissociation heater 53. Switch 63 is placed in its closed position so that current is applied to the preheater 11 for heating its coils. The magnet 91 is operated and opens the valve 90 fully. The fulgurite 53 is cold, and its resistance therefore high, so that the current through the winding of the relay 64 is not snfiicient to attract its armature.

The fluid or gaseous medium is passed into the coils of the preheater 1l and is superheated during its passage therethrough and its temperature is raised thereby to a point above the ignition point of the fuel 46. The hot medium. passes out of the preheater 11 and through the fulgurite tube 53 and into contact with the fuel, and on account of the high temperature of the medium the fuel is ignited automatically.

` The passage of the preheated medium through the fulgurite tube 53 raises the temperature of the tube in a manner similar to that described in Patent- No. 1,459,729 issued to Ine June 26, 1923, the application for which was copending herewith. Its conductivity is now increased somewhat7 permitting the passage of some electric current through it. This current heats the fulgurite still further but it is not suliiciently great to operate relay 64.

u The fluid or gaseous medium is adapted to supply oxygen to maintain combustion of the fuel, as previously described.

Continued combustion of the fuel 46 still further raises the temperature within the The products of combustion, as well as so much of the medium as is unconsumed pass out through the passages 541-., 57, the valve 55 having been set to interconnect these passages at the con'nnencement of operation. They pass through the heat exchange member, giving up a part of their heat to the incoming vapor within the inner pipe 36. They are then led to the utility 59, heating lthe same and finally may be permit- (ed to escape in any desired manner.

.The ten'iperature of the fulgurite 53 is again raised by the combustion of the fuel and thus its electrial conductivity is increased so that the current in its circuit becomes suliicient to operate the marginal relay 64. The consequent attraction of its armature opens the contact and thus the electric circuit of the passages of the preheater 11 and of the magnet 91 is deenergized. This reduces the temperature of the preheater through the passages of which the vapor passes, the temperature being controlled or determined by the conductivity of the fulguritc 53 and also reduces the amount ot fluid agent supplied as well as its pressure.

It will be seen that the electro-responsive means 6-1t and 91 operate and release as the conductivity of the fulgurite 53 increases or decreases. The closure of the contact 65 may therefore be intermittent or periodic and thus the temperature of the preheater may be accurately determined according to variations in temperature of combustion of the fuel and vapor.

During the periods when the circuit of the preheater 11 is deenergized the incoming medium is superheated by the heat exchange member 35. Thus combustion, having been initiated by the action of the preheater 11, is maintained by a direct reaction of the heat resulting from combustion upon the incoming active medium.

After the device started, the valve may be shiftedA to a position in which the passages 56. 57 are interconnected. Thus the unconsumed vapors are withdrawn from a Zone of the furnace below the fuel, and therefore somewhat lower in temperature than those in passage 54. By suitable manipulation of the valve at intervals. the temperature of the space 3S of the heat exchange member. and of the utility 59, may be closely controlled.

The ash may be blown out of the com partments 82, 33 by closing 'alvc 55 and opening the trapdoors 84.

The oi'ieration may be continued as long as desired and when the apparatus is to be shut down the switch 63 is opened. lVhen cool a new supply of fuel may be inserted, ready for subsequent operation.

1n the operation of the modified form of Sil lill) system shown in Figs. 4 and 5, Water is admitted in limited quantities by the needle valvel 72 into the pipe 7l and the inner tube S6 of the: heat exchange chamber 35. An electric current is caused to flow through the conductors 70 of the heat exchange chamber, the inti-fnsity of the current uith respect to the resistance of the conductors being such that the energy dissipated raises the temperature of the liquid within the pipe 36 and causes it to vaporize. The generated steam leaves the inner tube 36 and passes through the passageway 37 into the preheater 1l Where the same operation occurs as it has been previously described. The current through the conductors 7() of the heat exchange. chamber 35 may he disconnected either automatically or manually after the device has been started. ln the embodiment illustrated in the drawings, the current is automatically disconnected by the opening of contact but it `is understood that the circuit of conductor 7() may include if dcsired a manually operable switch for controlling the circuit thereof independently of said contact.

Apparatus of preferred form has been illustrated and described as one embodiment of the invention. It is expressly understood, however, that the scope of the invention is not to be limited thereby, reference being had to the appended claims for that purpose.

7hat I claim is: f

1. The method of initiating and maintaining combustion, which `consists of passing an oxygen carrying medium into a fuel at a temperature higher than the ignition point of the fuel, and passing the products of combustion through a heat exchange member to cause them to give up their heat to incoming medium.

2. The method of initiating and maintainingconibustion which consists of passing an oxygen carrying medium through a heat exchange member and into a fuel, the medium beingsuperheated to a temperature above the ignition point of the fuel by an exterior source of energy until combustion commences, and passing the products of combustion through the heat exchange memherto superheat the incoming medium independently of the exterior source.

3. The method of initiating and maintaining combustion which consists of passing an oxygen carrying medium through a heat exchange member, superheating the medium to a predetermined temperature by an exterior source of energy, passing the medium into contact with a fuel having an ignition point loiver than said temperature, automatically controlling the heating of the medium by the exterior source by the heat of combustion, and passing the products of combustion through the heat exchange member to impart the heat thereof to the incoming medium. Y

4. The method of initiating and maintaining conibustion, which consists of initially preheating by electricity a stream of an oxygen carrying agent to a relatively high temperature, passing the agent into contact with a fuel having an ignition point lower than said temperature, automatically controlling the electrical heating by the heat ot' combustion, and subse uently assisting the preheating oil' the incoming agent by imparting to it heat of the products of combustion. i

5. The method of controlling combustion which consists of superheating a gaseous agent in tivo Ways, passing the heated agent into a fuel and automatically discontinuing at least one of said ways of superheating the agent when the temperature of combustion of the fuel and agent exceeds a prede-` termined point.

6. The method of controlling combustion which consists of superheating a medium in two ways, initially employing only one Way of heating. passing the heated medium into a fuel, and automatically discontinuing said one way of heating the medium When the tenu'ierature of combustion of the fuel and medium exceeds a predetermined point.

T. The method of controlling combustion which consists of superheating a medium in two ways, one of which requires the connection of an outside source of energy, passing the heated medium into a fuel, and automatically disconnecting the outside source of energy when the temperature of combustion of the fuel and medium exceeds a predetermined point.

8. The method producing heat which consists of heating a combustible fluid to a relatively high temperature, passing the fluid into a combustion chamber containing fuel having an ignition point lower than said temperature, passing the products of combustion into a heat exchange member to impart heat therefrom to incoming fiuid, and controlling the temperature of the Huid according to variations in Ithe temperature within said chamber.

9. The method of producing heat which consists of heating a combustible medium to a relatively high temperature, passing the medium into a. combustion chamber containing fuel having an ignition point lower than said temperature, and passing the products of combustion through a heat exchange member to impart hea-t therefrom to incoming medium, and varying the temperature of the medium proportionally to variations in the temperature within said chamber.

10. The method of initiating and maintaining combustion which consists of initially superheating a gaseous medium, passing the medium into a fuel at a temperature nestjes higher than the ignition point of the fuel, automatically discontinuing the superheating after combustion of the fuel has commenced, and imparting heat from the escaping products of combustion and unconsumed vapors to the lincoming medium.

11. The method of generating heat, Which consists of preheating a medium and passing it into contact with a fuel at a temperature above the ignition point of the fuel, and imparting heat from the products of combustion and unconsumed vapors to incoming medium.

12. The method of generating heat, which consists of preheating a medium and passing it through a heat exchange member into contact With a fuel at a temperature above the ignition point of the fuel, and passing the products of combustion and unconsumed medium into the heat exchange memher to impart a portion of the heat thereof to incoming vapor.

13. In a heat generating system, the combination of a fuel chamber, means for pass-- ing an oxygen carrying agent into the chamher, means energized by an external source of energy for heating the agent prior to its contact therewith, and means energized by the heat of combustion for heating the agent.

14. In a heat generating system, the combination of a fuel chamber', means for passing an oxygen carrying agent into the chamber, means energized by an external source of energy for heating the vapor to a teme perature higher than the ignition point of the fuel prior' to its contact therewith, means energized by the heat of combustion for heating the agent, and automatic means for disconnecting the external source of energy after combustion has been initiated.

15. In a heat generating system, the combination of a tubular resistor connected thereto and adapted to receive a gaseous medium, means for supplying electric energy to the resistor, a furnace connected to the resistor and arranged to receive the medium therefrom, and a heat exchange member for passing incoming and outgoing medium through adjacent passages.

16. In a heat generator, the combination of a tubular resistor connected thereto and adapted to receive a gaseous medium, means for supplying electric energy to the resistor, a furnace connected to the resistor and arranged to receive the medium therefrom, means for controlling the electric energy supplied to the resistor, and other means independent of the electric energy for superheating the medium.

17. In a heat generating system, the combination of a tubular resistor connected thereto andadapted to receive vapor, means for supplying electric energy to the resistor,

a furnace connected tothe resistor and arranged to receive vapor therefrom, means comprising a temperature responsive device Within the furnace and an electro-responsive device outside of the furnace for controlling the electric energy Supplied to the resistor, and independent means for superheating the vapor.

18. In a heat generatingsystem, the combination of a tubular resistor, a furnace adapted to be supplied With superheated vapor therefrom, means responsive to the temperature Within said furnace for controlling the temperature of the resistors, and means actuated by combustion for maintaining the temperature of incoming vapor relatively high. y

19. A heat generator comprising a tubular resistor adapted to super-heat vapor, means for supplying electric energy for heating the resistor, a furnace arranged to receive superheated vapor from the resistor, means for controlling the electric energy supplied to the resistor in accordance with the internal temperature of the furnace, and means for superheating the incoming vapor independently of electric energy.

20. In a heat generating system, the com` bination of a furnace, a plurality of tubular resistor units connected to form a succession of vapor passages, temperature responsive means positioned Within the furnace adapted to conduct electricity only when hot, electro-responsive means outside of the furnace responsive to variations in resistance of said temperature responsive means for varying the temperature of the resistor units, and a heat exchange member independent of the electro-responsive means for superheating the incoming vapor.

21. In a heat generating system, the combination of a furnace, a plurality of resistor units connected to form a succession of vapor passages leading to the furnace, means for supplying electric energy to lthe resistor units for raising the temperature of the vapor, temperature responsive means positioned Within the furnace adapted to conduct electricity only when hot, electroresponsive means outside of the furnace responsive to variations in resistance of the temperature responsive means and adapted to control the elect-ric energy supplied to the resistor units, and other means actuated by the heat of combustion for superheating the incoming vapor.

22. In a heat generator, a furnace containing fuel, means for initially igniting the fuel comprising means for passing into the fuel a fluid medium, means for heating the medium and passing it to the interior of the furnace, means for supplying electric energy to said heating means, and means for discontinuing automatically the supply of lao electric energy after combustion of the fuel begins; and other means for supplying heat of the resultant combustion to the medium.

23. In a heat Generator, the combination of a tubular resistor adapted to conduct a fluid medium, means for supplying electric energy to the resistor, a furnace connected to the resistor and arranged to receive vapor therefrom, means for varying the electric energy supplied to the resistor, and means inde aendent of the electric energy for superheatin the medium.

24. n a heat generating system, the combination of a furnace having a fuel chamber, means for conducting a gaseous medium into the fuel chamber of the furnace including a heater actuated by electric energy for raising the temperature of the medium above the ignition point of the fuel, other means for preheating the medium by heat from the furnace, and means responsive to the combustion of the fuel for deenergizing the electric heater.

25. In a heat generator, a furnace containing fuel, means for heating a gaseous fluid to a temperature above the ignition point of said fuel, means for passing said heated fluid into the furnace, and means actuated by combustion of the fuel and said highly heated fluid, for heating the fluid loefore it enters said first mentioned heating means.y

26. In a heat generator, the combination of a furnace containing fuel, means for passing a stream of fluid into the furnace at a temperature above the ignition point of the fuel, electrical means for heating the fluid, a. temperature responsive. device actuated by the heat of combustion for rendering the electrical means inactive, and other means responsive to variations in temperature Within the furnace for varying the temperature of the incoming fluid.

27. In a heat generator, the combination of a furnace containing a fuel, a conductor for leading a gaseous medium to the furnace, two means for heating the medium in the ccnductor and means responsive to heat generated in the furnace for .cutting off one of the medium heating means.

28. In a heat generator, the combination of a furnace containing a fuel, and means for conducting a hot gas to the furnace, two means automatically influenced conversely by the heat generated in the furnace for superheating the gas before it enters the furnace, a conductor for leading gas to the furnace, two means for heating the gas in the conductor and means responsive to heat generated in the furnace for cutting off one of the gas conductor heating means.

29. In a heat generator, the combination of a furnace containing a fuel, and means for conducting a hot gas to the furnace, two means automatically controlled by the heat generated in the furnace for superheating the gas before it enters the furnace, one of the controlled means reducing the heat imparted to. the gas as the furnace heat increases, and the other increasing the heat imparted to the gas as the furnace heat increases, a conductor for leading gas to the furnace, two means for heating the gas in the conductor and means responsive to heat generated inthe furnace for cutting off one of the gas conductor heating means.

30. In a heat generator, the combination of a furnace containing a fuel, and means for conducting a hot gas to the furnace, two means automatically controlled by the heat generated in the furnace for superhcatinr the gas before it enters the furnace, one o the controlled means changing the amount of heat imparted to the gas proportionally to the temperature of the furnace and the other changing the amount of heat imparted to the gas in inverse relation to the temperature of the furnace.

31. The method of initiating and maintaining coinbustion, which consists of passing a stream of gaseous medium into a fuel at a tempeature higher than the vignition point of the fuel, and automatically varying the rato of flow of the medium according to variations in the resultant temperature.

32. The method of initiating and maintaining con'ibustion, which consists of passing a current of gaseous medium intol a fuel at a temperature higher than the ignition point of the'fuel, and automatically reducing the current the resultant temperature increases.

The method of controlling combustion which consists of passing a current of highly heated gaseous mediuni'into a fuel, and automatically reducing the current l OU when the resultant temperature of the gaseous medium and that produced by the combustion of the fuel reaches a predetermined point.

34. The meth-od of initiating and maintaining con'ibustion, which consists of passing a stream of air into a fuel at a temperature higher than the ignition point of the fuel, and automatically varying' the rate of flow of the `air according to variations in the resultant temperature.

The method of initiating and maintaining combustion, which consists of passing a current of air into a fuel at a teniperature higher than the ignition point of the fuel, and automatically reducing the current as the result-ant temperature increases. f

36. The method ef controlling combustion which consists of passing a current of highly1 heated air into a fuel, and automatically reducing the current when the resultant temperature of the air and that produced by llS the combustion of the fuel reaches a prede" termined point.

37. The method of producing heat which consists of' heating an oxygen carrying meA Vdium to a relatively high temperature, passing the medium at a predetermined rate of flow into a combustion chamber containingfuel having an ignition point lower than said temperature, and automatically varying the temperature and rate of ow of the medium according to variations in the temperature within said chamber.

38. The method of producing heat which consists of heating an oxygen carrying medium tora relatively high temperature, passing the medium at a j )redetermined rate of flow into a combustion chamberv containing fuel having an ignition point lower than said temperature, and automatically varying the temperature proportionately and the rate of flow of the medium inversely to variations in the temperature within said chamber.

39. The method of producing heat which consists of heating an oxygen carrying mcdium to a relatively high temperature, passing the medium at a predetermined rate of flow into a combustion chamber' containing fuel having an ignition point lower than said temperature, passing the products of combustion through a heat exchange member to impart heat therefrom to incomingI medium, and varying the temperature and rate ofv flow of the medium according to variations in the temperature within said chamber.

40. The method of producingl heat which. consists of heating au oxygen carrying medium to a relatively high temperature, pass- `ing the medium at a predeterminedl rate of flow into a combustion chamber containing fuel having an ignition point lower than said temperature, passing the products of con'ibustion through a heat exchange member to impart heat therefrom to incoming medium, and varying the temperature proportionately and the rate of flow of the medium inversely to variations in the tcmj'ierature within said chamber.

4l. In a heat generator, the combination with a furnace having a chamber containing fuel, and means for conducting a stream of gaseous fluid into the fuel chamber at au initial temperature above the ignition point of the fuel, of means for restricting a portion of the passage actuated by the heat of the furnace, means for prelieating the fluid, and a single temperature responsive means for controlling the restricting means and the preheating means.

42. In a heat generator, the combination with a combustion chamber containing fuel and a connected ash compartment having a discharge door, means for passing a gaseous fluid into said chamber and compartment,

an outlet Ipassage for said fluid, and a valvearranged to Idirect the fluid from the combustion chamber to said outlet passage or to close the outlet passage whereby said gaseous liuid may be utilized to blow ash out of said compartment through the discharge door.

43. In a heat generator, the combination with a combustion chamber containing fuel, and an ash compartment, of means for passing a gaseous-fluid into the chamber at a temperature above the ignition point of the fuel for initiating combustion, and means for passing the fiuid from the fuel chamber to the ash compartment for transferring the ash.

44. In a heat generator, the combination with a combustion chamber containing fuel, of means for passing a gaseous fluid into and out of the chamber at a temperature above the ignition point of the fuel for initially igniting the fuel and clearing the chamber of ash.

45. A heat generator comprising a combustion chamber containing fuel, means for passing a stream of air into the chamber at a temperature higher than the ignition point of the fuel, and temperature responsive means positioned Within the chamber and actuated by the resultant temperature of the hot air and the burning fuel for controlling the stream of air.

46. The method of generating heat which consists of passing a stream of hot gas into a fuel, and rising the {iovv of the gas to remove ash from the fuel.

47. The method of generating heat which consists of passing a stream of hot gas into a fuel, at a temperature above the ignition point of the fuel, and using the flow of the gas to remove ash from the fuel.

48. A furnace containing fuel, a non-juxtaposed utility, a connecting element for Sli leading hot gases from the furnace to the utility, means for leading a gas to the furnace through the same connecting element, and means dependent upon the temperature within the furnace for controlling the admission of the gas to the furnace.

49. A furnace comprising a combustion chamber, a plurality of chambers adjacent the combustion chamber disposed at different levels and means for withdrawing heated gases from any desired one of said adjacent chambers.

50. A furnace comprising a combustion chamber, a plurality of chambers adjacent the combustion chamber disposed at different levels, a conduit for withdrawing heated gases from said furnace, and adjustable means for connecting the conduit with said adjacent chambers.

5l. In a heat generating system, the combination of a furnace having a fuel chamber, means for conducting a gaseous medium into the fuel chamber including a heater energized by an external source of heat for raising the temperature of the medium above the ignition point of the fuel, other means for preheating the medium by heat from the furnace, and means controlled by the temperature in the fuel chamber for cutting off said external source of heat.

52. In a heat generating system, the cornbination of a furnace having a fuel chamber, means for conducting a gaseous medium into the fuel chamber including a heater energized by an external source of heat for raising the temperature of the medium above the ignition point of the fuel, other 15 means for preheatng the medium by heat from the furnace, and means controlled by the temperature in the fuel chamber'for cutting off said external source of heat and for governing the admission of the medium to the fuel chamber.

53. In a. heat generator, the combination of a furnace containing fuel, means for conducting a hot gas to the furnace and two means automatically influenced conversely by the heat generated in the furnace for superheating the gas before it enters the furnace.

In Witness whereof, I have hereunto set my hand this 6th day of December, 1921.

IVILLIAM S. HADAWAY, Jn. 

